queue_delayed_work_on(9)

queue_delayed_work_on(9) 💅

okay bestie, welcome to the Kernel API Manual — today’s main character is queue_delayed_work_on, and she is lowkey iconic. ✨

🎀 NAME 🎀

queue_delayed_work_on — queue work on specific CPU after delay. Periodt.

✨ SYNOPSIS ✨

No cap, here’s the signature:

bool queue_delayed_work_on (int cpu , struct workqueue_struct *wq ,
struct delayed_work *dwork , unsigned long delay );

🫶 ARGUMENTS 🫶

• cpu — CPU number to execute work on.
• wq — workqueue to use.
• dwork — work to queue.
• delay — number of jiffies to wait before queueing.

🌸 DESCRIPTION 🌸

So we queue the delayed_work to a specific CPU. For non-zero delays, the caller must ensure it is online and can’t go away. Lowkey this is the important part: if a caller fails to ensure this, they may get dwork->timer queued to an offlined CPU, and this will prevent queueing of dwork->work unless the offlined CPU becomes online again. 😭 That’s the whole vibe check.

🔥 RETURN 🔥

false if work was already on a queue, true otherwise. If delay is zero and dwork is idle, it will be scheduled for immediate execution. Slay. 💅

🌈 SEE ALSO 🌈

Kernel file ./kernel/workqueue.c is where it all lives, and the workqueue friend group is giving family reunion, iykyk:

• for_each_pool(9), for_each_pool_worker(9), for_each_pwq(9), worker_pool_assign_id(9), unbound_effective_cpumask(9)
• get_work_pool(9), worker_set_flags(9), worker_clr_flags(9), worker_enter_idle(9), worker_leave_idle(9)
• find_worker_executing_work(9), move_linked_works(9), assign_work(9), kick_pool_pick(9), kick_pool(9)
• wq_worker_running(9), wq_worker_sleeping(9), wq_worker_tick(9), wq_worker_last_func(9), wq_node_nr_active(9)
• wq_update_node_max_active(9), get_pwq(9), put_pwq(9), put_pwq_unlocked(9), pwq_tryinc_nr_active(9)
• pwq_activate_first_inactive(9), unplug_oldest_pwq(9), node_activate_pending_pwq(9), pwq_dec_nr_active(9), pwq_dec_nr_in_flight(9)
• try_to_grab_pending(9), work_grab_pending(9), insert_work(9), queue_work_on(9), select_numa_node_cpu(9)
• queue_work_node(9), mod_delayed_work_on(9), queue_rcu_work(9), worker_attach_to_pool(9), worker_detach_from_pool(9)
• create_worker(9), set_worker_dying(9), idle_worker_timeout(9), idle_cull_fn(9), maybe_create_worker(9)
• manage_workers(9), process_one_work(9), process_scheduled_works(9), worker_thread(9), rescuer_thread(9)
• check_flush_dependency(9), insert_wq_barrier(9), flush_workqueue_prep_pwqs(9), __flush_workqueue(9), drain_workqueue(9)
• flush_work(9), flush_delayed_work(9), flush_rcu_work(9), cancel_work_sync(9), cancel_delayed_work(9)
• cancel_delayed_work_sync(9), disable_work(9), disable_work_sync(9), enable_work(9), disable_delayed_work(9)
• disable_delayed_work_sync(9), enable_delayed_work(9), schedule_on_each_cpu(9), execute_in_process_context(9), free_workqueue_attrs(9)
• alloc_workqueue_attrs(9), init_worker_pool(9), put_unbound_pool(9), get_unbound_pool(9), wq_calc_pod_cpumask(9)
• apply_workqueue_attrs(9), unbound_wq_update_pwq(9), wq_adjust_max_active(9), destroy_workqueue(9), workqueue_set_max_active(9)
• workqueue_set_min_active(9), current_work(9), current_is_workqueue_rescuer(9), current_is_workqueue_mem_reclaim(9), workqueue_congested(9)
• work_busy(9), set_worker_desc(9), print_worker_info(9), show_one_workqueue(9), show_one_worker_pool(9)
• show_all_workqueues(9), show_freezable_workqueues(9), rebind_workers(9), restore_unbound_workers_cpumask(9), work_on_cpu_key(9)
• freeze_workqueues_begin(9), freeze_workqueues_busy(9), thaw_workqueues(9), workqueue_unbound_housekeeping_update(9), workqueue_set_unbound_cpumask(9)
• workqueue_sysfs_register(9), workqueue_sysfs_unregister(9), workqueue_init_early(9), workqueue_init(9), llc_count_cores(9)
• llc_populate_cpu_shard_id(9), precompute_cache_shard_ids(9), workqueue_init_topology(9)

okay that’s the whole page, bestie 🫶 — source/version is ./kernel, dated October 2026. Go queue something cute. 💖